The London-based rights group Amnesty International onThursdayraised concerns over continued attacks on Hong Kong's traditional freedoms, as the ruling Chinese Communist Party takes a more hands-on approach to the former British colony.

"Freedom of expression in Hong Kong came under attack as the government used vague and over broad charges to prosecute pro-democracy activists," the group said in its annual report, published on Thursday.

"The repeated use of vague charges against prominent pro-democracy movement figures appeared to be an orchestrated and retaliatory campaign by the authorities to punish and intimidate those advocating democracy or challenging the authorities," the report added.

It cited the charging last March of the founders of the 2014 pro-democracy movement with public order offenses for their role in the "Occupy Central" civil disobedience campaign, as well as the disqualification of newly elected pro-democracy lawmakers whose oaths of allegiance were judged insufficiently "solemn and sincere" by a ruling from Beijing.

The jailing last August of three former student leaders of the Occupy movement, Joshua Wong, Alex Chow and Nathan Law, to six, seven and eight months’ imprisonment respectively for their part in the movement was also a matter of concern, the report said.

And while a district court in the city sentenced seven police officers to two years' imprisonment last February for assaulting Occupy protester Ken Tsang, the decision was followed by "an orchestrated campaign attacking Hong Kong's judiciary" in the state-run Chinese media, it said.

The group’s Hong Kong director Mabel Au hit out at a string of prosecutions under "vague" public order charges.

"In 2017, we saw a lot of these kinds of charges, a situation that is far from ideal," Au said. "This will have a chilling effect, and citizens will think that they could be arrested and tried on some vague charge if they take to the streets in protest."

"These were clearly peaceful gatherings, and yet we still had these criminal charges, for example, causing a public nuisance, which is totally vague, really," she said.

During the 2014 protests, which called for fully democratic elections for chief executive and Legislative Council (LegCo), a panel of 18 independent experts working for the U.N. Human Rights Committee said Beijing's insistence on vetting electoral candidates for the post of Hong Kong's chief executive was in violation of international human rights treaties.

Hong Kong has signed and ratified the U.N.'s International Covenant on Civil and Political Rights, passed by the General Assembly in 1966, while Beijing has signed but not ratified it.

'Ruthless campaign' in China

Across the internal immigration border in mainland China, the Chinese authorities are continuing an unprecedented crackdown on dissent, Amnesty's annual report said, citing a "ruthless campaign of arbitrary arrests, detention, imprisonment and torture and other ill-treatment of human rights lawyers and activists."

It said the authorities are continuing with the widespread use of "residential surveillance in a designated location."

"[This is] a form of secret incommunicado detention that allowed the police to hold individuals for up to six months outside the formal detention system, without access to legal counsel of their choice, their families or others, and placed suspects at risk of torture and other ill-treatment," the report said.

It has been used to curb the activities of human rights defenders, including lawyers, activists and religious practitioners, it said.

"We don't expect to see any improvement in the human rights situation in the short term," Poon said. "Unless the government comes to understand clearly that they are an important member of the international community, and, as such, have a duty to abide by human rights convenants that they have signed."

Chinese human rights lawyer Xie Yan, who was charged with "incitement to subvert state power" amid a nationwide operation targeting the legal profession that began inJuly 2015, said the administration of President Xi Jinping has no interest in applying the rule of law.

"Legally and constitutionally speaking, it is not a wise move to persecute lawyers, because it will in fact destroy the whole legal system," Xie told RFA. "Trust in the legal system is also trust in this government, and its constitutional right to rule."

Amnesty's report singled out the northwestern region of Xinjiang in particular, saying that Beijing has increasingly used “national security” as justification for restriction of human rights and detention of activists

In Xinjiang, a new emphasis on “social stability” resulted in increased technological surveillance, armed street patrols and security checkpoints and implemented an array of intrusive policies violating human rights, it said.

"Authorities set up detention facilities within the [region], variously called “counter extremism centers”, “political study centers” or “education and transformation centers”, in which people were arbitrarily detained for unspecified periods and forced to study Chinese laws and policies," it said.

Reported by Wong Lok-to for RFA's Cantonese Service, and by Shi Shan for the Mandarin Service. Translated and edited by Luisetta Mudie.